Engine/Transmission (1998.5 - 2002) Lift Pump Pressure

[DavidC]

I finally have a Westach 0-16psi fuel pressure gauge installed.

Indicated pressures are as follows (not towing,truck only) post filter (filter was changed 7 days ago). Truck has 34000 miles registered.



Idle=11-12psi

cruise=8psi

WOT=6-7psi

Do these numbers lean toward a failing pump?

The Dodge manual states that minimum idle pressure should not be under 10 psi. That kind of takes the warranty issue out of the picture. One interesting note is that the pressure increases about 1-2psi during braking kind of like fuel sloshing around the pickup tube. All pressures were taken with 1/2 tank of fuel. I have read posts where idle pressure after a new lift pump was installed of 16psi and the Dodge manual specifies that the return pop off valve should open at 14psi. Am I missing something here that the pop off valve is not limiting pressure in this case.

 

[Duane George]

pressure.....

i just installed my fuel pressure gauge. when i did the gauge didn't read any pressure. after fighting with my dealer on the lift pump being out. i went ahead and put in a new one.

idle is 16 psi

cruising is 14 psi

wot is 10 psi

when you take your foot out of the throttle you should see you psi go back up.

i would guess you lift pump is getting bad.

take it in or replace it.



good luck!



Duane

 

[Jvann]

15 psi at idle

Just installed a new lift pump and was surprised at the difference between the old one and new one. Using SW guage the old one showed 11 to 12 psi at idle and around 9 to 10 at cruise speed but would drop to 4 psi on hard throttle when towing or accelarating hard. New one idles at 14 to 15 psi and holds at 12 to 13 psi when accelarating. I haven't gotten it below 12 psi yet. I would suggest that you keep a close eye on yours and if your pressures fall much more Just go ahead and replace it as it's not a really big deal to do it yourself and keep the stealer out of the picture. Around 150 for the new pump. I had 45K when I replaced mine. Hope this helps! LOL

 

[RobbyRam]

I took a picture of my gauge at idle, and WOT and recorded the PSI's. They repaced my lift pump, no questins asked!

 

[DavidC]

Thanks for the help guy's. I pretty much thought the pump was going south but alot of you have already been where i am now. Just thought I would get some opinions before visiting the local Cummins dealer.